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Kumar V, Roy S, Behera BK, Swain HS, Das BK. Biofloc Microbiome With Bioremediation and Health Benefits. Front Microbiol 2021; 12:741164. [PMID: 34912305 PMCID: PMC8667556 DOI: 10.3389/fmicb.2021.741164] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 10/25/2021] [Indexed: 12/29/2022] Open
Abstract
The biofloc system has recently attracted great attention as a cost-effective, sustainable, and environmentally friendly technology and expected to contribute toward human food security (Zero Hunger SDG 2). It is also expected that this endeavor can be adopted widely because of its characteristics of zero water exchange and reduced artificial feeding features. In the biofloc system, the flocs which are generally formed by aggregation of heterotrophic microorganisms, serve as natural bioremediation candidates. These microbes effectively maintain water quality by utilizing the nutrient wastes, mostly originated from digested, unconsumed, and metabolic processes of feed. Additionally, the flocs are important sources of nutrients, mainly a protein source, and when these are consumed by aquaculture animals they improve the growth performance, immunity, and disease tolerance of host against pathogenic microbial infection. Here in this review, we focus on recent advances that could provide a mechanistic insight on how the microbial community developed in the biofloc system helps in the bioremediation process and enhances the overall health of the host. We have also tried to address the possible role of these microbial communities against growth and virulence of pathogenic microbes.
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Affiliation(s)
- Vikash Kumar
- Aquatic Environmental Biotechnology and Nanotechnology (AEBN) Division, ICAR-Central Inland Fisheries Research Institute (CIFRI), Barrackpore, India
| | - Suvra Roy
- Aquatic Environmental Biotechnology and Nanotechnology (AEBN) Division, ICAR-Central Inland Fisheries Research Institute (CIFRI), Barrackpore, India
| | - Bijay Kumar Behera
- Aquatic Environmental Biotechnology and Nanotechnology (AEBN) Division, ICAR-Central Inland Fisheries Research Institute (CIFRI), Barrackpore, India
| | - Himanshu Sekhar Swain
- Fisheries Enhancement and Management (FEM) Division, ICAR-Central Inland Fisheries Research Institute (CIFRI), Barrackpore, India
| | - Basanta Kumar Das
- ICAR-Central Inland Fisheries Research Institute (CIFRI), Barrackpore, India
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Bruce TJ, Ma J, Sudheesh PS, Cain KD. Quantification and comparison of gene expression associated with iron regulation and metabolism in a virulent and attenuated strain of Flavobacterium psychrophilum. JOURNAL OF FISH DISEASES 2021; 44:949-960. [PMID: 33591637 DOI: 10.1111/jfd.13354] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Iron is essential for growth and virulence in most pathogenic bacterial strains. In some cases, the hosts for these pathogenic bacteria develop specialized strategies to sequester iron and limit infectivity. This in turn may result in the invading pathogens utilizing high-affinity iron transport mechanisms, such as the use of iron-chelating siderophores, to extend beyond the host defences. Flavobacterium psychrophilum, the causative agent of bacterial coldwater disease (BCWD) in salmonids, relies on iron metabolism for infectivity, and the genome of the model CSF-259-93 strain has recently been made available. Further, this strain serves as a parent strain for a live-attenuated vaccine strain, B.17, which has been shown to provide rainbow trout with protection against BCWD. To elucidate specific gene expression responses to iron metabolism and compare strain differences, both F. psychrophilum strains were grown under iron-limiting conditions and 26 genes related to iron metabolism were mapped for 96 hr in culture via qPCR analyses. Results indicate increased production of the ferrous iron transport protein B (FITB; p =.008), and ferric receptor CfrA (FR 1; p =.012) in the wild-type CSF-259-93 strain at 72 hr and 96 hr post-exposure to iron-limiting media. In the B.17 vaccine strain, siderophore synthase (SS) expression was found to be downregulated at 72 hr, in comparison with 0h (p =.018). When strains were compared, FITB (p =.021), FR1 (p =.009) and SS (p =.016) were also elevated in B.17 at 0 hr and TonB outer protein membrane receptor 1 (TBomr1; p =.005) had a lower expression at 96 hr. Overall, this study demonstrated strain-related gene expression changes in only a fraction of the iron metabolism genes tested; however, results provide insight on potential virulence mechanisms and clarification on iron-related gene expression for F. psychrophilum.
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Affiliation(s)
- Timothy J Bruce
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID, USA
| | - Jie Ma
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID, USA
| | - Ponnerassery S Sudheesh
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID, USA
| | - Kenneth D Cain
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID, USA
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Skin bacteria of rainbow trout antagonistic to the fish pathogen Flavobacterium psychrophilum. Sci Rep 2021; 11:7518. [PMID: 33824380 PMCID: PMC8024317 DOI: 10.1038/s41598-021-87167-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/24/2021] [Indexed: 12/15/2022] Open
Abstract
Rainbow trout fry syndrome (RTFS) and bacterial coldwater disease (BCWD) is a globally distributed freshwater fish disease caused by Flavobacterium psychrophilum. In spite of its importance, an effective vaccine is not still available. Manipulation of the microbiome of skin, which is a primary infection gate for pathogens, could be a novel countermeasure. For example, increasing the abundance of specific antagonistic bacteria against pathogens in fish skin might be effective to prevent fish disease. Here, we combined cultivation with 16S rRNA gene amplicon sequencing to obtain insight into the skin microbiome of the rainbow trout (Oncorhynchus mykiss) and searched for skin bacteria antagonistic to F. psychrophilum. By using multiple culture media, we obtained 174 isolates spanning 18 genera. Among them, Bosea sp. OX14 and Flavobacterium sp. GL7 respectively inhibited the growth of F. psychrophilum KU190628-78 and NCIMB 1947T, and produced antagonistic compounds of < 3 kDa in size. Sequences related to our isolates comprised 4.95% of skin microbial communities, and those related to strains OX14 and GL7 respectively comprised 1.60% and 0.17% of the skin microbiome. Comparisons with previously published microbiome data detected sequences related to strains OX14 and GL7 in skin of other rainbow trout and Atlantic salmon.
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Ngo TPH, Smith P, Bartie KL, Thompson KD, Verner-Jeffreys DW, Hoare R, Adams A. Antimicrobial susceptibility of Flavobacterium psychrophilum isolates from the United Kingdom. JOURNAL OF FISH DISEASES 2018; 41:309-320. [PMID: 29064104 DOI: 10.1111/jfd.12730] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/08/2017] [Accepted: 08/11/2017] [Indexed: 06/07/2023]
Abstract
Routine application of antimicrobials is the current treatment of choice for rainbow trout fry syndrome (RTFS) or bacterial coldwater disease (BCWD) caused by Flavobacterium psychrophilum. In this study, the antimicrobial susceptibilities of 133 F. psychrophilum isolates, 118 of which were from the UK, were evaluated by broth microdilution and disc diffusion methods following VET04-A2 and VET03-A guidelines of Clinical and Laboratory Standards Institute (CLSI), respectively. Isolates were categorized as wild type (fully susceptible, WT) or non-wild type (NWT) using normalized resistance interpretation (NRI)-determined cut-off values (COWT ). Broth microdilution testing showed that only 12% of UK isolates were WT to oxolinic acid (MIC COWT ≤ 0.25 mg/L) and 42% were WT for oxytetracycline (MIC COWT ≤ 0.25 mg/L). In contrast, all the isolates tested were WT (MIC COWT ≤ 2 mg/L) for florfenicol, the main antimicrobial for RTFS control in the UK. Disc diffusion-based COWT values were ≥51 mm for 10 μg amoxicillin, ≥44 mm for 30 μg florfenicol, ≥30 mm for 2 μg oxolinic acid and ≥51 mm for 30 μg oxytetracycline. There was a high categorical agreement between the classifications of the isolates by two testing methods for florfenicol (100%), oxytetracycline (93%) and oxolinic acid (99%).
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Affiliation(s)
- T P H Ngo
- Institute of Aquaculture, University of Stirling, Stirling, UK
- Division of Aquacultural Biotechnology, Biotechnology Center of Ho Chi Minh city, Ho Chi Minh city, Vietnam
| | - P Smith
- National University of Ireland, Galway, Ireland
| | - K L Bartie
- Institute of Aquaculture, University of Stirling, Stirling, UK
| | - K D Thompson
- Moredun Research Institute, Pentlands Science Park, Penicuik, UK
| | - D W Verner-Jeffreys
- The Centre for Environment, Fisheries and Aquaculture Science, The Nothe, Weymouth, UK
| | - R Hoare
- Institute of Aquaculture, University of Stirling, Stirling, UK
| | - A Adams
- Institute of Aquaculture, University of Stirling, Stirling, UK
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Hossain MI, Sadekuzzaman M, Ha SD. Probiotics as potential alternative biocontrol agents in the agriculture and food industries: A review. Food Res Int 2017; 100:63-73. [DOI: 10.1016/j.foodres.2017.07.077] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/29/2017] [Accepted: 07/31/2017] [Indexed: 12/13/2022]
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Ghosh B, Cain KD, Nowak BF, Bridle AR. Microencapsulation of a putative probiotic Enterobacter species, C6-6, to protect rainbow trout, Oncorhynchus mykiss (Walbaum), against bacterial coldwater disease. JOURNAL OF FISH DISEASES 2016; 39:1-11. [PMID: 25272249 DOI: 10.1111/jfd.12311] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/15/2014] [Accepted: 08/19/2014] [Indexed: 06/03/2023]
Abstract
Flavobacterium psychrophilum is the causative agent of bacterial coldwater disease (BCWD), which has a major impact on salmonid aquaculture globally. An Enterobacter species, C6-6, isolated from the gut of rainbow trout, Oncorhynchus mykiss (Walbaum), has been identified as a potential probiotic species providing protection against BCWD. This study examined the effects of alginate microencapsulation on the protective efficacy of C6-6 against BCWD in vivo when administered to rainbow trout fry orally or by intraperitoneal (IP) injection. Viable C6-6 bacteria were microencapsulated successfully, and this process (microencapsulation) did not significantly deteriorate its protective properties as compared to the administration of non-microencapsulated C6-6 bacteria. Both oral and IP delivery of C6-6 achieved significantly better protection than control treatments that did not contain C6-6 bacteria. The highest relative percent survival (RPS) resulted from IP delivery (71.4%) and was significantly greater than the highest oral RPS (38.6%). Successful intestinal colonization was not critical to protective effects of C6-6. The study showed that C6-6 administration, with or without encapsulation, was a viable choice for protecting fry from BCWD especially when administered intraperitoneally.
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Affiliation(s)
- B Ghosh
- National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Launceston, Tasmania, Australia
| | - K D Cain
- Department of Fish and Wildlife Resources and the Aquaculture Research Institute, University of Idaho, Moscow, Idaho, USA
| | - B F Nowak
- National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Launceston, Tasmania, Australia
| | - A R Bridle
- National Centre for Marine Conservation and Resource Sustainability, University of Tasmania, Launceston, Tasmania, Australia
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Fuente MDL, Miranda CD, Jopia P, González-Rocha G, Guiliani N, Sossa K, Urrutia H. Growth inhibition of bacterial fish pathogens and quorum-sensing blocking by bacteria recovered from chilean salmonid farms. JOURNAL OF AQUATIC ANIMAL HEALTH 2015; 27:112-122. [PMID: 26000731 DOI: 10.1080/08997659.2014.1001534] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The main goal of this study was to find bacterial isolates with the ability to inhibit the growth of the fish pathogens Aeromonas hydrophila, Vibrio anguillarum, and Flavobacterium psychrophilum and to inhibit the blockage of the quorum-sensing (QS) system. A total of 80 gram-negative strains isolated from various freshwater Chilean salmonid farms were studied. We determined that 10 strains belonging to the genus Pseudomonas inhibited at least one of the assayed fish pathogens. Of these, nine strains were able to produce siderophores and two strains were able to inhibit the growth of all assayed pathogenic species. When the 80 strains were examined for QS-blocking activity, only the strains Pseudomonas sp. FF16 and Raoultella planticola R5B1 were identified as QS blockers. When the QS-blocker strains were analyzed for their ability to produce homoserine lactone (HSL) molecules, thin-layer chromatography analysis showed that both strains were able to produce C6-HSL- and C8-HSL-type molecules. Strain R5B1 did not show growth inhibition properties, but strain FF16 also led to inhibition of growth in A. hydrophila and F. psychrophilum as well as to siderophore production. Pseudomonas sp. FF16 exhibited potentially useful antagonistic properties and could be a probiotic candidate for the salmon farming industry.
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Affiliation(s)
- Mery de la Fuente
- a Laboratorio de Biotecnología e Ingeniería Acuícola, Departamento de Ingeniería Ambiental y Recursos Naturales, Facultad de Ingeniería , Universidad Católica de la Santísima Concepción , Alonso de Ribera 2850, Concepción , Chile
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Tapia-Paniagua ST, Vidal S, Lobo C, Prieto-Álamo MJ, Jurado J, Cordero H, Cerezuela R, García de la Banda I, Esteban MA, Balebona MC, Moriñigo MA. The treatment with the probiotic Shewanella putrefaciens Pdp11 of specimens of Solea senegalensis exposed to high stocking densities to enhance their resistance to disease. FISH & SHELLFISH IMMUNOLOGY 2014; 41:209-221. [PMID: 25149590 DOI: 10.1016/j.fsi.2014.08.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/30/2014] [Accepted: 08/07/2014] [Indexed: 06/03/2023]
Abstract
Aquaculture industry exposes fish to acute stress events, such as high stocking density, and a link between stress and higher susceptibility to diseases has been concluded. Several studies have demonstrated increased stress tolerance of fish treated with probiotics, but the mechanisms involved have not been elucidated. Shewanella putrefaciens Pdp11 is a strain isolated from healthy gilthead seabream (Sparus aurata L.) and it is considered as probiotics. The aim of this study was to evaluate the effect of the dietary administration of this probiotics on the stress tolerance of Solea senegalensis specimens farmed under high stocking density (PHD) compared to a group fed a commercial diet and farmed under the same conditions (CHD). In addition, during the experiment, a natural infectious outbreak due to Vibrio species affected fish farmed under crowding conditions. Changes in the microbiota and histology of intestine and in the transcription of immune response genes were evaluated at 19 and 30 days of the experiment. Mortality was observed after 9 days of the beginning of the experiment in CHD and PHD groups, it being higher in the CHD group. Fish farmed under crowding stress showed reduced expression of genes at 19 day probiotic feeding. On the contrary, a significant increase in immune related gene expression was detected in CHD fish at 30 day, whereas the gene expression in fish from PHD group was very similar to that showed in specimens fed and farmed with the conventional conditions. In addition, the dietary administration of S. putrefaciens Pdp11 produced an important modulation of the intestinal microbiota, which was significantly correlated with the high number of goblet cells detected in fish fed the probiotic diet.
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Affiliation(s)
- S T Tapia-Paniagua
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - S Vidal
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - C Lobo
- Instituto Español de Oceanografía, Centro Oceanográfico de Santander, 39080 Santander, Spain
| | - M J Prieto-Álamo
- Universidad de Córdoba, Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Ctra. Madrid, Km. 396, 14071 Córdoba, Spain
| | - J Jurado
- Universidad de Córdoba, Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Ctra. Madrid, Km. 396, 14071 Córdoba, Spain
| | - H Cordero
- Universidad de Murcia, Departamento de Biología Celular e Histología, Campus de Espinardo s/n, 30100 Murcia, Spain
| | - R Cerezuela
- Universidad de Murcia, Departamento de Biología Celular e Histología, Campus de Espinardo s/n, 30100 Murcia, Spain
| | - I García de la Banda
- Instituto Español de Oceanografía, Centro Oceanográfico de Santander, 39080 Santander, Spain
| | - M A Esteban
- Universidad de Murcia, Departamento de Biología Celular e Histología, Campus de Espinardo s/n, 30100 Murcia, Spain
| | - M C Balebona
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - M A Moriñigo
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain.
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C De B, Meena DK, Behera BK, Das P, Das Mohapatra PK, Sharma AP. Probiotics in fish and shellfish culture: immunomodulatory and ecophysiological responses. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:921-971. [PMID: 24419543 DOI: 10.1007/s10695-013-9897-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 12/06/2013] [Indexed: 06/03/2023]
Abstract
Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view.
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Affiliation(s)
- Bidhan C De
- Central Inland Fisheries Research Institute, Barrackpore, Kolkata, 700120, West Bengal, India
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De la Fuente M, Vidal JM, Miranda CD, González G, Urrutia H. Inhibition of Flavobacterium psychrophilum biofilm formation using a biofilm of the antagonist Pseudomonas fluorescens FF48. SPRINGERPLUS 2013; 2:176. [PMID: 23667820 PMCID: PMC3650236 DOI: 10.1186/2193-1801-2-176] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 04/02/2013] [Indexed: 12/02/2022]
Abstract
The most important bacterial pathology currently occurring in Chilean freshwater salmon farming is the cold-water disease produced by the psychrotrophic bacteria Flavobacterium psychrophilum. The main aim of this study was to characterize the inhibitory activity of an antagonist strain on the formation of biofilms of a F. psychrophilum strain. The antagonistic strain Pseudomonas fluorescens FF48 was isolated from the sediment beneath the salmon cages of a freshwater Chilean salmon farm and was identified by using the 16S rRNA gene sequence analysis. The production of siderophores, mainly during the stationary phase of growth of the antagonist strain was demonstrated using the Chrome Azurol S method and through F. psychrophilum inhibition under iron saturation conditions. Subsequently, the effect of the antagonist supernatant on the formation of F. psychrophilum biofilm was tested using the crystal violet staining method observing an inhibition of the growth of F. psychrophilum, but no effect was observed when iron saturation concentrations were used. Furthermore, when the antagonist strain was previously deposited on the support, it completely inhibited the formation of F. psychrophilum biofilms, but when both bacteria were inoculated simultaneously no inhibitory effect was detected. In conclusion, it was demonstrated that FF48 strain is able to inhibit the formation of F. psychrophilum biofilms in vitro probably mediated by the siderophore production, suggesting its potential use as a biocontrol biofilm in freshwater fish rearing systems to prevent the persistence of biofilms of the fish pathogenic species F. psychrophilum.
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Affiliation(s)
- Mery De la Fuente
- Biofilms and Environmental Microbiology Laboratory, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile
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Burbank DR, Lapatra SE, Fornshell G, Cain KD. Isolation of bacterial probiotic candidates from the gastrointestinal tract of rainbow trout, Oncorhynchus mykiss (Walbaum), and screening for inhibitory activity against Flavobacterium psychrophilum. JOURNAL OF FISH DISEASES 2012; 35:809-816. [PMID: 22913277 DOI: 10.1111/j.1365-2761.2012.01432.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 10/31/2011] [Accepted: 11/22/2011] [Indexed: 06/01/2023]
Abstract
In this study, 318 bacterial strains were isolated from the gastrointestinal (GI) tracts of 29 rainbow trout, Oncorhynchus mykiss (Walbaum). These bacteria were screened in vitro for their ability to inhibit growth of Flavobacterium psychrophilum, the causative agent of coldwater disease. Bacteria observed to inhibit F. psychrophilum growth were further screened against rainbow trout bile, as an indicator of their ability to survive in the GI tract. This screening resulted in narrowing the pool to 24 bacterial isolates. Those 24 isolates were then tested for pathogenicity in rainbow trout by intraperitoneal injection. Following a 28-day challenge, eight isolates were shown to cause direct mortality and were eliminated from further study. As a result, 16 bacterial isolates were identified as probiotic candidates with the potential to control or reduce disease caused by F. psychrophilum.
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Affiliation(s)
- D R Burbank
- Department of Fish and Wildlife, University of Idaho, Moscow, ID, USA
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Korkea-aho TL, Papadopoulou A, Heikkinen J, von Wright A, Adams A, Austin B, Thompson KD. Pseudomonas M162 confers protection against rainbow trout fry syndrome by stimulating immunity. J Appl Microbiol 2012; 113:24-35. [PMID: 22548608 DOI: 10.1111/j.1365-2672.2012.05325.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To evaluate the antagonistic effect of Pseudomonas M162 against Flavobacterium psychrophilum. METHODS AND RESULTS The antagonistic activity of M162 was tested in vivo and in vitro, and its mode of action examined by siderophore production and immunological responses of rainbow trout (Oncorhynchus mykiss) fry. Pseudomonas M162 inhibited the growth of Fl. psychrophilum in vitro and increased the resistance of the fish against the pathogen, resulting in a relative per cent survival (RPS) of 39·2%. However, the siderophores produced by M162 did not have an inhibitory effect on Fl. psychrophilum. In fish fed with M162, the probiotic colonized the gastrointestinal tract and stimulated peripheral blood leucocyte counts, serum lysozyme activity and total serum immunoglobulin levels after 3 weeks from the start of feeding. CONCLUSIONS This study showed the potential of Pseudomonas M162 as a probiotic by reducing the mortalities that occurred during an experimental Fl. psychrophilum infection, resulting mainly through the immunostimulatory effects of the bacterium. SIGNIFICANCE AND IMPACT OF THE STUDY Rainbow trout fry syndrome (RTFS) causes high mortalities during the early life stages of the fish's life cycle, partly because their adaptive immunity has not yet fully developed. Thus, immunomodulation by probiotics could be an effective prophylactic method against RTFS.
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Affiliation(s)
- T L Korkea-aho
- Institute of Aquaculture, University of Stirling, Stirling, UK.
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